Revista De Microbiologia最新文献_第4页

Properties of a new fungal b -galactosidase with potential application in the dairy industry 一种新型真菌b -半乳糖苷酶的性质及其在乳制品工业中的应用前景

Revista De Microbiologia Pub Date : 1999-07-01 DOI: 10.1590/S0001-37141999000300014

R. Cruz, V. Cruz, J. Belote, Marcelo de Oliveira Khenayfes, Claudia Dorta, Luı́za Helena dos Santos Oliveira

{"title":"Properties of a new fungal b -galactosidase with potential application in the dairy industry","authors":"R. Cruz, V. Cruz, J. Belote, Marcelo de Oliveira Khenayfes, Claudia Dorta, Luı́za Helena dos Santos Oliveira","doi":"10.1590/S0001-37141999000300014","DOIUrl":"https://doi.org/10.1590/S0001-37141999000300014","url":null,"abstract":"b-Galactosidase or b-D-galactoside-galactohydrolase (EC. 3.2.1.23) is an important enzyme industrially used for the hydrolysis of lactose from milk and milk whey for several applications. Lately, the importance of this enzyme was enhanced by its galactosyltransferase activity, which is responsible for the synthesis of transgalactosylated oligosaccharides (TOS) that act as functional foods, with several beneficial effects on consumers. Penicillium simplicissimum, a strain isolated from soil, when grown in semi-solid medium showed good productivity of b-galactosidase with galactosyltransferase activity. The optimum pH for hydrolysis was in the 4.04.6 range and the optimum pH for galactosyltransferase activity was in the 6.07.0 range. The optimum temperature for hydrolysis and transferase activity was 55-60°C and 50°C, respectively, and the enzyme showed high thermostability for the hydrolytic activity. The enzyme showed a potential for several industrial applications such as removal of 67% of the lactose from milk and 84% of the lactose from milk whey when incubated at their original pH (4.5 and 6.34, respectively) under optimum temperature conditions. When incubated with a 40% lactose solution in 150 mM McIlvaine buffer, pH 4.5, at 55°C the enzyme converted 86.5% of the lactose to its component monosaccharides. When incubated with a 60% lactose solution in the same buffer but at pH 6.5 and 50°C, the enzyme can synthetize up to 30.5% TOS, with 39.5% lactose and 30% monosaccharides remaining in the preparation.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"1 1","pages":"265-271"},"PeriodicalIF":0.0,"publicationDate":"1999-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88325666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Equine leukoencephalomalacia associated with ingestion of corn contaminated with fumonisin B1 马脑白质软化症与摄入被伏马菌素B1污染的玉米有关

Revista De Microbiologia Pub Date : 1999-07-01 DOI: 10.1590/S0001-37141999000300011

C. Mallmann, J. Santurio, P. Dilkin

引用次数: 20

Therapeutic properties of whey used as fermented drink 乳清作为发酵饮料的治疗特性

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200015

T. Kar, A. Misra

引用次数: 22

Genetic variability of HIV-1 isolates from Minas Gerais, Brazil 巴西米纳斯吉拉斯州HIV-1分离株的遗传变异

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200010

A. Proietti, E. F. Barbosa, Janaína Guernica Silva, A. F. Carvalho, E. Kroon, P. P. Ferreira

引用次数: 3

Nitrate levels and stages of growth in hypernodulating mutants of Lupinus albus. I. N2 fixation potential 白Lupinus albus高调节突变体的硝酸盐水平和生长阶段。1 . N2固定电位

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200001

H. A. Burity, M. Chamber-Perez, M. D. C. C. P. Lyra, M. Figueiredo

{"title":"Nitrate levels and stages of growth in hypernodulating mutants of Lupinus albus. I. N2 fixation potential","authors":"H. A. Burity, M. Chamber-Perez, M. D. C. C. P. Lyra, M. Figueiredo","doi":"10.1590/S0001-37141999000200001","DOIUrl":"https://doi.org/10.1590/S0001-37141999000200001","url":null,"abstract":"This work aimed to evaluate physiological parameters, nodulation response and N2 fixation rate in mutants of Lupinus albus in comparison with the standard Multolupa cultivar. Two nitrate levels (0 and 5mM) and two evaluation periods (7 and 10 weeks) were used. Significant differences were observed among genotypes, in relation to fresh nodule weight, nitrate levels and growth stages. The overall average for nitrate level differed between them where 5mM severely inhibited the number of nodules, reaching a 49.5% reduction in relation to treatment without nitrate. There were no behaviour differences among genotypes, nor among evaluation periods. Although the level of nitrate did not influence the production of shoot dry matter in relation to the average among levels applied, the L-135 genotype, being an inefficient mutant, reached very low values. There were no significant differences in electron allocation coefficient (EAC) among nitrate levels, nor among genotypes studied. However, the evaluation periods revealed differences, where the EAC for the seventh week had a higher value than that for the tenth week, when a 5mM aplication was evaluated. The N2 fixation rate (N2 FIX) showed the existence of the nitrate interference in fixation, given that the application of 5mM severely reduced. However, there were no differences among the genotypes and it was noted that the fixation rate was much higher in those that received nitrate. The L-88 and L-62 genotypes were the ones that have shown best adaptability in this experiment, thus being able to be recommended for new studies with higher nitrate levels and different evaluation periods. The nitrate (5mM) interferes in the nitrogen fixation rate, given that all the genotypes were affected by the level applied.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"7 1","pages":"91-97"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88274727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Protease production during growth and autolysis of submerged Metarhizium anisopliae cultures 绿僵菌生长和自溶过程中蛋白酶的产生

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200004

G. U. Braga, R. Destéfano, C. Messias

{"title":"Protease production during growth and autolysis of submerged Metarhizium anisopliae cultures","authors":"G. U. Braga, R. Destéfano, C. Messias","doi":"10.1590/S0001-37141999000200004","DOIUrl":"https://doi.org/10.1590/S0001-37141999000200004","url":null,"abstract":"The growth and autolysis of two strains of the entomopathogenic deuteromycete fungus Metarhizium anisopliae var. anisopliae were evaluated in medium containing casein or glucose as carbon source. Parameters such as economic coefficient and degree of autolysis were determined for each strain. Protease production was determined throughout the growth and autolysis phases of the cultures on medium under conditions of protease induction (in the presence of casein as sole source of carbon and nitrogen). The fungus was shown to utilize casein as a carbon/energy source in a more efficient manner than glucose. The autolysis shown by the strains was intense under both types of growth conditions, reaching up to 62.7% of the dry mass produced and started soon after the depletion of the exogenous carbon source. The relationship between the proteolytic activities of the two strains evaluated varied significantly (a maximum of 19.78 on the 5th day and a minimum of 2.03 on the 16th day of growth) during the various growth and autolysis phases, clearly showing that the difference between the growth curves and the difference in the kinetics of enzyme production may decisively affect the process of strain selection for protease production.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"84 1","pages":"107-113"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77946809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 22

Discrimination of members of the Mycobacterium avium complex by polymerase chain reaction 禽分枝杆菌复合体成员的聚合酶链反应鉴别

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200011

M. Sircili, E. Roxo, S. Leão

引用次数: 4

Uptake of iron from different compounds by enteroinvasive Escherichia coli 肠侵入性大肠杆菌从不同化合物中摄取铁

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200012

Monique Dall´Agnol, M. Martinez

引用次数: 6

Nitrate levels and stages of growth in hypernodulating mutants of Lupinus albus. II. Enzymatic activity and transport of N in the xylem sap 白Lupinus albus高调节突变体的硝酸盐水平和生长阶段。2。木质部汁液中N的酶活性和运输

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200002

H. A. Burity, M. Chamber-Perez, M. D. C. C. P. Lyra, M. Figueiredo

{"title":"Nitrate levels and stages of growth in hypernodulating mutants of Lupinus albus. II. Enzymatic activity and transport of N in the xylem sap","authors":"H. A. Burity, M. Chamber-Perez, M. D. C. C. P. Lyra, M. Figueiredo","doi":"10.1590/S0001-37141999000200002","DOIUrl":"https://doi.org/10.1590/S0001-37141999000200002","url":null,"abstract":"O estudo enzimatico e o transporte de N na seiva do xilema foi realizado visando observar a influencia de diferentes niveis de nitrato e estagios de crescimento da planta em mutantes tratadas quimicamente. Varios estresses induzem a reducao no crescimento da planta da qual resulta na acumulacao de aminoacidos livres, amidas ou ureidos, tanto na parte aerea como nas raizes e nodulos. A atividade de enzimas e decisiva em evitar produtos inibidores da nitrogenase pelo amonio, porem poucas sao as informacoes deste mecanismo com o qual o xilema carrega estes produtos, em compensacao, este processo, pode ser a chave da funcao em evitar acumulacao de aminoacidos nas celulas dos nodulos infectados. O comportamento das enzimas nitrato redutase (NR), fosfoenolpiruvato carboxilase (PEPC), glutamina sintetase (GS) e dos compostos nitrogenados derivados da fixacao como: N-a-amino, N-ureidos e N-amida em genotipos mutados foi observado. A atividade da enzima nitrato redutase foi altamente inflenciada pela aplicacao de nitrato apresentando valores bastante superiores em relacao a nao aplicacao do nitrato, independentemente dos genotipos, sendo que o melhor periodo de avaliacao foi na decima semana. O genotipo L-62, com caracteriticas de resistencia ao nitrato, mostrou de forma bem evidenciada que a enzima PEPC e inibida pela presenca de nitrato. O genotipo L-135 (nod- fix-) apresentou atividade da GS extremamente baixo, mostrando desta forma que a GS e uma enzima altamente correlacionada com a fixacao. Em relacao ao melhor estagio de crescimento para a GS, o Lupinus albus, deve ser avaliado na setima semana.","PeriodicalId":21211,"journal":{"name":"Revista De Microbiologia","volume":"21 1","pages":"98-103"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87531185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Toxic metabolites from culture filtrate of Fusarium oxysporum and its effects on cucumber cells and plantlets 尖孢镰刀菌培养滤液毒性代谢物及其对黄瓜细胞和植株的影响

Revista De Microbiologia Pub Date : 1999-04-01 DOI: 10.1590/S0001-37141999000200003

I. S. Melo, E. Piccinin

引用次数: 9